| 摘要 |
PURPOSE:To obtain a high switching speed and also to minimize a forward voltage drop by a method wherein a defective layer is formed on a substrate beforehand and after applying heat treatment thereto, a heavy metal atom is introduced thereinto. CONSTITUTION:B2O5 dissolved in powdered ethyl alcohol is applied 5 on a p-type emitter layer 2 of a substrate in 4-layer structure of PNPN, a high-temperature treatment is applied in a dry O2 after drying it in N2, and a defective layer 6 is made by a surplus B diffusion. Then, a heat treatment is applied consecutively for 30min to stabilization, and the substrate is cooled down at the rate of 1 deg.C/min. After that Au 7 is metallized, and a heat diffusion is carried out in dry N2. Thus a crystal defect is controlled for formation, therefore a desired characteristic can be reproduced effectively, and a contradictory relation between switching speed and power loss can also be settled. For formation of the defective layer, abrasion or introduction of a high-speed ion is also applicable. |
